title: 1-Deazaadenosine: synthesis and activity of base-modified hammerhead ribozymes.
abstract: The incorporation of 1-deazaadenosine (c1A, 1b) into a hammerhead ribozyme and the resulting catalytic activity is described. For this purpose the phosphoramidite 2a and the 3'-phosphonate 2b as well as Fractosil-linked 1-deazaadenosine (3b) were prepared. The methoxyacetyl group was used for the 6-amino group protection and the triisopropylsilyl residue was introduced as the 2'-OH protecting group. Replacement of residues A14and A15.1 of the hammerhead ribozyme by 1-deazaadenosine resulted in a significantly reduced catalytic activity. Substitution of the A6, A9 and A13 residues has only a minor influence. The findings observed on ribozymes modified with 1-deazaadenosine were compared with those containing other adenosine analogues.
authors.affiliation: Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie, Universität Osnabrück, Barbarastrasse 7, D-49069 Osnabrück, Germany. fraseela@rz.uni-osnabrueck.de
authors.forename: F
authors.initials: F
authors.lastname: Seela
authors.forename: H
authors.initials: H
authors.lastname: Debelak
authors.forename: N
authors.initials: N
authors.lastname: Usman
authors.forename: A
authors.initials: A
authors.lastname: Burgin
authors.forename: L
authors.initials: L
authors.lastname: Beigelman
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D016337:RNA, Catalytic / Q000138:chemical synthesis* / Q000737:chemistry* / Q000378:metabolism; D014372:Tubercidin / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D009843:Oligoribonucleotides; D016337:RNA, Catalytic; C048086:1-deazaadenosine; D014372:Tubercidin